Mechanism for reverse drives



April 1, 1941. w. M. THOMAS arm.

MECHANISM FOR REVERSE DRIVES Filed Dec. 29, 1939 mu in 1 Ame I M 2 momcyfii cf Q Patented Apr. 1, 1941 MECHANISM FOR REVERSE DRIVES William Miles Thomas, Four Oaks, England, and

Jean Cotal, Paris, France Application December 29, 1939, Serial No. 311,684 In France November 7, 1938 2 Claims.

The present invention has for its object a mechanism for reverse drive, which provides for the forward motion and the back motion of the driven shaft, and is chiefly characterized by the fact that it comprises a braking device, preferably of the electro-magnetic type, which is adapted to hold the said driven shaft in position when it has a tendency to be operated, with the engine running and the reversing device at the dead centre. 1;

The said mechanism is applicable to systems of propulsion for vessels, vehicles and various means of transportation, and herein the engine can rotate at the dead centre without being subjected to a driving which is improper and may even be dangerous. In particular, in the case of vessels, by holding the propeller in the fixed position, it prevents it from striking, when in rotation, against foreign bodies by which it may be damaged.

In the accompanying drawing, which is given solely by way of example:

Fig. 1 is a longitudinal section of a reversing mechanism adapted for electro-mechanical control, with an electro-magnet for stopping the driven shaft and a permanent planetary reducer, according to the invention.

Fig. 2 is a partial section of the same device, but without a permanent reducer.

In the embodiment represented in Fig. 1, the mechanism consists essentially of two sets of secured to the driven shaft I5 which enters into the driving shaft I, for which it ensures the exactly concentric position by means of suitably placed bearings I 6 and I1.

The operation is as follows:

For the forward motion, the armature 9 adheres to the rotatable electro-magnet 6 which is now energized. The planetary pinion carrier 5 and the sun wheel 2 are thus connected together, and the annulus 3 is driven at the same speed and in the same direction as the driving shaft I. By the operation of the reducing set I2, I3, I4, the driven shaft I5 is also driven in the same direction but at reduced speed.

For the back motion, the armature 9 adheres to the electro-magnet I which is now energized. The planetary pinion carrier 5 is thus held fast, and. the annulus 3 is driven by the planetary pinions l in the contrary direction to the sun wheel 2 and to the driving shaft I. The driven shaft I5, by theoperation of the reducing set I2, I3, I4, will thus rotate at reverse drive with a reduced speed.

hypocycloidal gearing. The first set is mounted,

on the driving shaft I, and constitutes the re versing device. It comprises a sun wheel 2 which is keyed to the shaft I, an annulus 3 which is loose on this shaft, and planetary pinions I, mounted on a planetary pinion carrier 3.

The operation of this set of gearing is controlled by an electro-magnet 6 secured to the driving shaft I, and by an electro-magnet I secured to the casing 3. An armature 9, common to both electro-magnets, is secured to the planetary pinion carrier 5 of the planetary set which is loosely centered on the driving shaft I. A second electro-magnet I0 which may be either secured to the electro-magnet I or fixed upon the casing 8 independently of the electro-magnet l is adapted to hold in the fixed position an armature II which participates in the rotation of the annulus 3 mounted loose on the driving shaft I.

The second planetary gear set serves as a permanent speed-reducer. The small sun wheel I2 of this set is secured to the annulus 3 of the other set, and the large annulus I3 is fixed upon the casing. The planetary pinion carrier I! is For the/braking, the electro-magnet I0 is alone energizediflan d it holds the annulus 3 and hence the planetary pinion carrier I4 and the driven shaft I5 in the fixed position. This shaft is maintained in the stopped position even though it should be urged by the rotation of the engine and by,the passive resistances, or by the propelling devices such as propellers, wheels or the like.

Fig. 2 shows a modification which does not comprise a permanent reducer, and herein the braking takes place directly upon the driven shaft I5, by means of the annulus 3 to which it is secured.

Obviously, the invention is not limited to the embodiments herein described and represented, which are given solely by way of example.

In the case of Fig. 1, it is further possible to mount the braking armature directly upon the driven shaft.

It is evident that the braking device is applicable, irrespectively of the constructional form of the reversing device itself.

Having now described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A mechanism for reverse drive comprising in combination a driving shaft, a driven shaft, a sun wheel secured to said driving shaft, a rotatable annular wheel, a pinion carrier carrying at least one planetary pinion meshing with said sun wheel and with said annular wheel, selective means adapted to bring said pinion carrier sesaid carrier assumes an Qnopentlv M w m n which said can! wound in which said with one of said wh I 'lectlvely in three W Wm M m m m W W m m M W. M M m m m m M n m m m m M W w m mm w: m m m m m m m. w m

M m m. M m m 

